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Discussion Starter #1
I am in the middle of the proverbial Headstud, BPD, overhaul on my 6.0 and I am lucky enough to have a machine shop in the plant I work at.

The machinist is capable and willing to mill and/or grind my heads if needed after checking the flatness on a FARO CMM.

He suggested we could surface grind them to get them as flat as possible, but I remember reading on the SWAMPS website that they recommend a Ra 50 Surface Finish to allow the gasket to "hold".

Can anyone confirm this or even better provide an RMS number?

I tried to convert Ra to RMS but after much reading they are measuring two different ways and although you can convert them somewhat successfully, there is about a 11%-25% margin of error!

Any machinists in the house?
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tell your machinist the OEM gaskets are MLS
so from what I gather the surface finish is not as critical as it is for a 1 peice gasket

is there no way He can confirm the existing finish using a PROLIFOMETER and match it if you don't get a firm finish # ?

here is the only info I could find sos far
MLS gaskets, a surface finish of 30 RA or smoother is usually required.
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well I looked everywhere and can't find the RA /RMS #

If nothing Else call Bulletproof they have a machine shop they use right down the street who does all their 6.0 heads they will either know or can give you the phone #
 

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Discussion Starter #4
Thanks for the reply.

Swamps said 50 Ra for their "Cometic" brand MLS Gasket.

I planned on using OEM MLS Gaskets.

Where did you find 30 Ra?

From what I am learning, the smoother the better? But I think a polished finish would be unacceptable.

Another issue now, I measure the head thickness and I am at 3.74 to 3.737.

I've read the Ford spec. is 3.74. I really don't want to go through the trouble of grinding valve stems and resetting the seats.

I guess my options are the Swamps Cometic in oversize thickness, or refurbished heads.

Any suggestions?
 

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I even asked Cheezit but He didn't have a number he told Me to use a RMS gauge and match stock.

I found the other recommendation as a standard when using layered MLS gaskets.

if I were doing mine ( I did not have the luxury when ford was doing mine under warranty ).

I would have em cleaned up ( flat) and would have had hardened seats installed.

but definitely call Bullet proof they can probably get the info.

and yes I read a mirror/polished finish is no good also.
I wouldn't go with anything other than an OEM gasket myself.
 

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Here is who bulletproof uses

B & B Automotive Machine .936 W Broadway Rd
Mesa, AZ 85210-8440 (map)

(480) 649-8243
 

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Hey ak49er my head thickness was very close to what yours are at and they were never machined or taken off the truck since new and I have had no issues at all
 

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Discussion Starter #8
Thanks guys, for the responses, I'll call that shop on Monday.

@ Steve O

What do you mean by you have had no problems?

Did you have them milled and put them back on, just checked for flat or....?

I'm not tracking here, but would like to know what you meant.

Please explain more.
 

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Damnkids Motorsports
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You can also get copper headgaskets in any thickness you want. Doug @ GoGo would be the guy to talk to about those.
 

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it's an 02 05 08
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i wouldnt use anything other than oem gaskets on a 6.0 machine the heads,studs and oem gaskets and call it done
 

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Discussion Starter #12
So I measure one head last night, confirmed the 3.74 minimum, decided to go old school on the measuring, used the granite table, made three posts out of 1-2-3 blocks, with steel balls, shimmed them all to height, and used a surface gauge to measure the head surface which was now paralleled to the granite table. Got one set of readings, then switched the three points opposite, and confirmed the repeatability.

The head shows an arc with the center two cylinders .0025" less than the outer two, so looking at the head, fire surface up, it is dipped down at the two inner cylinders.

We will use the FARO to confirm these readings at lunch time.

I haven't checked the other head yet. If it is way out, the decision is easy,replace it, if it is "flat" or at .0025" again, risk it and run it?
 

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You can also get copper headgaskets in any thickness you want. Doug @ GoGo would be the guy to talk to about those.
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Interesting because varied thickness gaskets have been elusive for these forever ..are they a new product?
however there is also a reason MLS are used in this application so IDK if I would go that route ???
 

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ford advises against milling the heads period.their flatness check procedure is a joke and would pass on all but the worst cylinder head.that being said,everyone mills them.you need to magnaflux the heads for cracks around the seats before going any further though.
 

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I have a question..when people are replacing head gaskets and take their heads to get milled...what about the engine block itself? How are they ensuring the block deck is perfectly flat with the new gasket?

Thanks
 
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